Mechanism for swinging crane booms



Nov. 29, 1949 L. ROCKSTROM ETAL 2,489,326

MECHANISM FOR SWINGING CRANE BOOMS Filed Jan. 24, 1947 2 Sheets-Sheet l INVENTORS [eonardfqocislram BY Anion BrzyZz/a ATTORNEY Nov. 29, 1949 1... ROCKSTROM ETAL MECHANISM FOR SWINGING CRANE BOOMS 2 Sheets-Sheet 2 Filed Jan. 24, 1947 INVENTORS I 73 lem zardfiacltqirom BY Avian Brzylza ATTORNE Y I: A FIIL ZJ WW m 5 WM. 6 a

UNITED STATES PATENT OFFICE 2,489,326 MECHANISM FOR SWINGING CRANE BOOMS Leonard Rockstrom and Anton Briglia, Brooklyn, N. Y., assignors to Silent Hoist and Crane 00., 1110., Brooklyn, N. Y., a corporation of New York Application January 24, 1947, Serial No. 724,136

8 Claims.

The present invention relates in general to boom-type cranes and more particularly to an improved and novel mechanism for rotating or swinging the boom of such cranes relative to the control and operating elements of the present invention;

Fig. 3 is a vertical sectional view taken substantially throughthe center of the hydraulically supporting structure therefor. As will be apoperated boom swingingmechanism;

parent hereinafter, the invention while :being Fig. l is a horizontal sectional view taken subparticularly adaptable to a mobile crane unit and stantially on line i4 of Fig.3, of the hydraulidescribed and shown a being applied to such a cally operated boom swinging mechanism; unit, is not limited to such application but may Fig. 5 is an exploded view Of the coupling membe readily applied to various other types of cranes. 1o bers between the hydraulic unit and the mast;

It is an object of the present invention to pro- Fig. 6 is a fragmentary vertical sectional view vide a hydraulic actuated mechanism or motor, of a modified sealing arrangement ,for the imfor swinging the boom of a crane together with peller of the hydraulic unit; and its supporting mast, which is independent of the Fig. '7 is a fragmentary horizontal sectional mast and boom but which is coupled thereto by view of the elements ofFig. 6. means capable of absorbing misalignment. Referring first to Fig. 1, there is shown the Another object of the invention is to provide forward or boom end of a mobile crane unit an improved crane boom swinging mechanism wherein is incorporated the elements of the which is capable of use with a great number of present invention for rotating the boom and its different kinds and types of'loads'and for a great supporting mast. The mobile unit itself may be variety of purposes. of conventional design and parts thereof are Still anotherobject of the invention is to pro- ShOWIl merely for e ,DW'DO if illustrating the i 1 i d sealing means b t th application of the invention as the invention is movable and stationary elements of a hydraulic q y applicable to o types of cranes. The motor. crane unit includes a main chassis having longi- In connection with the above another object tudinai rails ll suitably braced and reinforced to of the invention is to provide a 'hydraulic'motor give the desired Strength and r i and has with an impeller rotatably movable therein havtraction Wheels, Such as e forward ing a vane seal actuated hydraulic pressure end, capable of being driven in a conventional on either Side of aidi ll manner from an engine included in the unit.

A more Specific object of the invention is to Centrally located in a substantially vertical provide a mechanism of the above type wherein position at the forward end of the mobile unit d fl ti in the mast of the crane and the 1s a mast 13. The mast I3 is supported adjacent porting structure therefor during varying load the upper and lower Ends thereof in semalignconditions are nottransmitted to the mechanism 3.3 mg hearings (I101? ShOWIl) contained in upper and employedito Swing the boom of the cram lower mast bearing housings l4 and I5, respec- A more ifi Object of the invention is to tively. The self-aligning bearings, which may be provide a hydraulic operated mechanism for 9 any Well known 'm type, hold the mast swinging the boom of a crane, which mechanism in place and permit rotation of the mast but no is coupled to the boom in such a manner that the appreciable axlallmwement thereofhydraulic mechanism forms a shock absorber for A framework mdloated generally, by reference load developed forces tending to swing the boom. nAlme.ra1 s gg 9 i g f the The above and other objects, advantages, and 2 21 3 g gg giz f i ggg g g'g 1 32??? f Yf a g i apparent from} is pivotally mounted at its lowerend on a horizontal 01 Y 3 m escnp 10.11 of preferreu boom trunnion 19 supported in a collar2ll clamped modlfieq i thfereof' In the to the mast 13 just above the lower bearing houslowmg Q 15 made to the ing I6. Carried in the forward end of the boom companylng S Whl0h3 are pulleys or sheaves 2| through which pass Fig. 1 1s a side view In elevation of a swinging Games 22 and 223 The m 22 Supports the boom crane structure embodying the present invention as it may be incorporated in a mobile crane;

Fig. 2 is a diagrammatic view of the pump, valve and associated hydraulic elements of the load block 23 and cable 22 supports the boom is in the manner shown and provides the means whereby the boom is elevated and lowered. A mast head 24 supports .a pair of sheaves, such as 21, which guide the cables 22 and 22' down through the hollow mast l3 to a pair of O idler sheaves 28 suitably supported from the chassis. From the sheaves 2B the cables 22 and 22 pass to drums, such as 29, power-driven from the self-contained motor through appropriate mechanisms and clutches. Only one of each of the two pairs of sheaves 27 and 28 and one of the drums 29 are shown in the drawings. The units of each pair are mounted side by side.

Secured to the mobile unit chassis and frame i; just below the mast l3 and in substantial axial alignment therewith, is the hydraulic mast rotating or boom swinging mechanism or motor, indicated generally by the reference numeral 3i, which has the component parts thereof referred to hereinafter by individual reference numerals. Willie in the preferred embodiment of the invention the hydraulic motor is mounted in the chassis and coupled to the mast, in a manner hereinafter described, it would be obvious that the motor could be mounted on the mast in a full floating arrangement and with a suitable torque arm or similar element or elements to take up the mast swinging pressure developed by the hydraulic motor on the mast.

In the preferred embodiment, as more clearly shown in Figs. 3 and 4, the hydraulic motor includes an upper fianged disc-shaped cylinder head 32 and a similar lower cylinder head 33. The cylinder heads 32 and 33 are strengthened and reinforced by integral web sections 36, and separating the two heads is a cylinder ring The inside surface of the ring 36 as well as the inside faces of the cylinder heads are lapped smooth for reasons hereinafter apparent, and bolts, such as 31, clamp the cylinder heads and ring together, as shown, to form the hydraulic chamber of the motor. Packing glands 32 at the joining surfaces thereof make these joints fluid tight.

Passing through the circular opening in the center of the two cylinder heads 32 and 33 is a short shaft or hollow cylinder 39. The shaft 39 is slightly larger in the section thereof located between the cylinder heads, and is supported for rotative movement by means of bearings 2. in each of the heads 32 and 33. Packing rings 32 and packing compressing nuts 43 threaded into the heads 32 and 33 surround the shaft 39 jacent the ends thereof and enable a fluid tight seal to be maintained between the shaft and the cylinder heads.

The upper end of the shaft 39, as best shown in Fig. 5, has a radial groove in the face thereof which is adapted to receive a tongue formed on the lower end of a bottom coupling member 44. By means of said tongue and groove, the shaft 39 is coupled to the member 44 and a ring sleeve ll surrounds the two at the joint to prevent displacement of one relative to the other. The coupling member 44 has extending from the upper face thereof a pair of diametrically opposed lugs or jaws 46 which engage radial openings such as 45 in a central coupling disc 48.

In a similar manner, lugs or jaws 46 on the lower end of an upper coupling member 46' engage other radial openings in the central coupling disc 48. The upper coupling member 44 is formed integral with, or suitably secured as by welding, to the lower end of the mast l3. Thus the shaft 39 of the hydraulic motor is coupled to the lower end of the mast l3 and as the shaft 39 is rotated about its axis in a manner about to be described, the mast will rotate therewith to give the desired swinging movement to the attached boom H3. The shafts l3 and the upper and lower coupling members and 'si respectively, and the coupling disc it, all have openings down through the centers thereof to permit passage therethrough of the boom elevating and load block operating cables 22 and 22.

In the preferred embodiment of the invention the depth of the notches 45 in the central coupling disc 43 are somewhat deeper than the radial dimensions of the lugs or jaws 43 and it on the lower and upper coupling members 4 8 and M respectively. This arrangement permits some misalignment, which may be caused by varying loads on the crane boom, between the mast l3 and the shaft 39 of the rigidly mounted hydraulic motor 3| while at the same time main taining the two units properly coupled together.

Thus the coupling unit is capable of absorbing the misalignment between the hydraulic motor and the mast l3.

Surrounding the enlarged section of the shaft as within the cylinder, and secured thereto by suitable means, as by welding, for rotation therewith, is a hydraulically operating member or impeller 59 which has a radially extending arm 39 slightly less in length than the inside radius of the cylinder ring 36. The upper and lower surfaces of the impeller arm 49 are lapped smooth and the height thereof, as shown in Fig. 3, is for all substantial purposes equal to the height of the cylinder ring 36, and the impeller arm it is adapted to move or rotate within the space defined by the inner lapped surfaces of the cylinder heads 32 and 33 and the cylinder ring 39. A fluid tight seal between the cylinder head faces and the adjacent surfaces of the impeller 49 is obviously desirable.

The free end of the impeller arm 39 has a vertical slot or groove throughout its entire height and within this slot is a freely movable vane 52. The exposed end of the vane 52 is slightly rounded to conform to the inside surface of the cylinder ring against which it is pressed by springs 53 carried in recesses in the impeller and working against the inner edge of the vane. The vane 52 extends the full height of the arm 49 and the exposed end contacting the cylinder wall forms a fluid tight seal thereat between the arm and the cylinder ring.

As more clearly shown in Fig. 4, the impeller arm 49 has formed therein a passageway 54 extending from one side of the arm to the other, and one side of this passageway is tapped to receive a hollow screw 56. Formed within the passageway 54 is a ball seat 51 and a similar seat 58 is formed on the inner end of the hollow screw 56. A small steel ball 59 is located within the passageway 54 in operative relation with the seats 5'! and 58. A second passageway 6| communicates with the chamber provided for the steel ball 59 in the passageway 54 and the slot or groove in which is mounted the vane 52.

The ball 59 and its co-operating seats 51 and 58 prevent the passage of the hydraulic fluid from one side of the impeller arm 49 to the other, but hydraulic pressure developed on either side of the arm is permitted to pass through the passageways 54 and 9! and work against the inner end of the vane 52 to hydraulically balance the vane against any pressure which might be caused by the hydraulic liquid leaking around and against the forward end of the vane. The pressure on the inner end of the vane 52 also assists the springs 53 in sealing the forward end which is in contact with the cylinder ring 36.

Secured in a recess 62 on the inside of the cylinder ring 36 by means of screws such as 63 is a hydraulic chamber dividing block 54. Block 64 carries a vane 66, the free end of which engages the cylindrical part of the impeller 50 surrounding the shaft 39. the vane 65 is shaped to conform with the cylindrical surface of the impeller 51! and springs 61 urge the vane into engagement therewith. The block 64 has contained therein a steel ball 68 The forward end of i with co-operating passageways including the pas- A modified arrangement of sealing the hydraulic motor impeller is shown in Figs. 6 and 7 and includes leather or similar sealing means. In this modification, the impeller arm 49 rotatable with the shaft 3% has on opposite faces thereof sealing members it of suitable material, such as leather, which are held in place by clamping plates ll. Similar seals 10 are secured to opposite sides of the stationary block 64 to seal the cylindrical section of the impeller and, if desired, the joints where the block meets the cylinder heads.

The cylinder ring 36 has hydraulic fluid admitting passageways or connections 12 and I2 located on opposite sides of the dividing block 64 whereby hydraulic fluid may be admitted to the chamber on either side of the impeller 50 to cause the same to rotate within the chamber. It will be apparent that rotation or oscillation of the impeller 5i produces similar movement in the mast l3 to thereby swing the crane boom l8 in the manner desired. Vents and drain plugs 13 are provided in the upper and lower cylinder heads to permit venting of the hydraulic chamber and the draining of the hydraulic fluid therefrom when such is desired or necessary.

The hydraulic motor or unit 3| may be 0perated from any suitable source of hydraulic fluid and Fig. 2, by way of example, illustrates the manner in which such a source of fluid may be associated with the motor. However, it will be obvious that various other equivalent arrangements can be employed. In the diagrammatic arrangement of Fig. 2, reference numeral 14 represents a hydraulic fluid pump and "it a four-way control valve of the suitable and well known type interconnected with associated elements including a relief valve 86 and the hydraulic motor 3| in the manner shown. The valve 16 enables the direction of flow of hydraulic fluid to the motor to be reversed and thereby reverse the direction of rotation of the impeller 59 in the hydraulic motor. The valve it also, and relief valve 86, provides a means for by-passing the hydraulic fluid around the hydraulic motor at which time the motor impeller 59 is hydraulically locked, and since such valves are well known, a full detailed description thereof will not be included herein.

From the above it will be evident that the present invention provides an easily and positively controlled hydraulically operated means which is simple and positive in operation, and which is attachable to a crane unit, either mobile or stationary, in such a manner that any deflection in the mast i3 or the supporting frame structure" is not transmitted to the impelling unit. Furthermore, the above arrangement pro vides a boom swinging mechanism which is entirely enclosed and which provides an arrangement forabsorbing, by means of the hydraulic fluid and its co-operating elements, the relief valve 86, shocks and sudden strains.

While the invention has been described in a preferred embodiment thereof, it will be obvious that various modifications may be made therein without departing from the spirit or essential attributes thereof, and it is desired, therefore, that only such limitations be placed thereon as are defined in the appended claims.

What is claimed is:

1. In a crane unit, a rotatable crane boom supporting mast, a hydraulic unit having a hydraulic chamber with a hydraulically actuated impeller therein, a coupling unit for coupling said impeller to said mast, said hydraulic unit being in substantial axial alignment with said. mast and the impeller thereof coupled through said coupling unit to an end of said mast, a source of pressure fluid in saidcrane unit, and valve means associated therewith whereby said fluid is admitted to said hydraulic unit to produce move ment of said impeller and corresponding movement of said mast and boom.

2. In a crane unit, a rotatable crane boom supporting mast, a hydraulic unit having a hydraulic chamber with a hydraulically actuated impeller adapted to rotate therein, a coupling unit for coupling said mast to said impeller for rotary movement therewith, said hydraulic unit being independent of said mast and coupled by said coupling unit to an end of said mast, a source of pressure fluid in said crane unit, valve means associated with said pressure fluid whereby said fluid is admitted to said hydraulic unit to produce rotary movement of said impeller, a fluid seal element movable with said impeller within said hydraulic unit and means including the pressure of said fluid in said hydraulic unit to urge said seal element into fluid sealing position with the walls of said hydraulic chamber.

3. In a crane, an upright and rotatable boom supporting mast, a framework included in said crane for supporting said mast adjacent the ends thereof, a hydraulic motor mounted on. said crane with the axis thereof substantially common to the axis of said mast, a hydraulically impelled member within said motor adapted for rotary movement, and coupling means for directly coupling said impeller to said mast whereby said mast and impeller rotate together, and means including said coupling means for absorbing misalignment between said mast and said hydraulic motor.

4. In a crane unit, an upright and rotatable boom supporting mast, a framework included in said unit supporting said mast, a hydraulic cylinder mounted on said unit with the axis thereof substantially common to the axis of said mast, a hydraulically impelled member within and adapted for rotary movement about the axis of said cylinder, means for axially coupling said mast to said impeller for rotation together about a substantially common axis and means including said coupling means for preventing strains in and deflections of said mast under varying 7, boom load conditions from being transmitted to said hydraulic cylinder and impeller.

5. In a craneunit, an upright rotatable boom supporting mast, a hydraulic motor independent of.-said mast, said motor including ahydraulically impelled member rotatablymovable on an axis substantially common to the axis of said mast, coupling meansfor coupling said member to said mast whereby said mast is rotated, and means including said coupling means for absorbing misalignment in the axis of said member and the axisof'said mast.-

6. Ina crane unit, an upright rotatable boom supporting'mast, a hydraulic motor independent of-saidmast, said motor including a hydraulic chamber containing. a hydraulically actuated impeller and a stationary member dividing said chamber into two parts, said impeller and said member having seals for hydraulicallysealing the tWoparts'of said chamber, meansincluding said member within said chamber for developing a hydraulic pressure on either side of saidimpeller to rotate the same in opposite directions, coupling means for coupling said impeller'to said mast whereby the mast and impeller-rotate together, and means including said coupling means for'absorbing misalignment between the axis of said impeller and the axis of said mast.

7. Ina crane unit, a rotatable boom supporting mast, azhydraulic unit having a hydraulic cham- 8 ber with a rotatable impeller and a fixed member'therein dividing said chamber into two parts, said mast being rotatable with said impeller, and means for developing a hydraulic pressure on either side of said fixed dividing member to rotate said impeller and mast.

8. In a crane unit, a rotatable boom supporting mast, a hydraulic unit having a hydraulic chamber with a rotatable impeller and a fixed member'therein dividing said chamber into two parts, saidmast being rotatable with said impeller, a source. of hydraulic fluid under pressure, and means including said fluid for developing a hydraulic pressure in either one at a time of said parts into which said hydraulic chamber is divided by said impeller and said fixed member to rotate said impeller and mast.

LEONARD ROCKSTROM. ANTON BRIGLIA.

REFERENCES CITED The: following references are of record in the file of this patent:

UNITED STATES PATENTS 

